*{
    padding:0px;
    margin:0px;
  }
  html,body,#app{
    width:100%;
    height:100%;
  }
  ul,ol{
    list-style: none;
  }
  a{
    text-decoration: none;
  }
  img{
    display: block;
  }

  /* 版心 */
  .main{
      min-width: 320px;
      max-width: 750px; 
      margin: 0 auto;
  }

  h1,h2,h3,h4,h5,h6{
    font-weight: normal;
  }